Page 171 - Formulas and Calculations for Petroleum Engineering

164 Formulas and calculations for petroleum engineering

Output(s)

W max : Maximum Allowable Mud Weight (ppg)

Formula(s)

P lo
W ¼ + W
max u
0:052 H
Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 150.

2.214 Subsea considerations—Casing pressure decrease when bringing well on choke

Input(s)
SICP: Shut in casing Pressure (psi)
CLPL: Choke Line Pressure Loss (psi)

Output(s)

P r : Casing Pressure Decrease when bringing well on choke (psi)

Formula(s)
P r ¼ SICP CLPL

Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 144.

2.215 Subsea considerations—Velocity through choke line

Input(s)

Gpm: Mud Circulation rate (gpm)
ID: Choke line ID (in.)

Output(s)
V: Velocity through Choke Line (ft/min)

Formula(s)

Gpm
V ¼ 24:5
ID 2

Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 148.

2.216 Surface test pressure required to frac the formation

Input(s)

FG: Fracture Gradient (psi/ft)
D: Depth (ft)
r: Mud Density (ppg)